1、IEEE Std 1458-20051458TMIEEE Recommended Practice for theSelection, Field Testing, and LifeExpectancy of Molded Case CircuitBreakers for Industrial Applications3 Park Avenue, New York, NY 10016-5997, USAIEEE Industry Applications SocietySponsored by thePetroleum and Chemical Industry Committee24 Jun
2、e 2005Print: SH95226PDF: SS95226IEEE Std 1458-2005(R2010) Approved 24 January 2005 Reaffirmed 8 December 2010 IEEE-SA Standards Board Abstract: A recommended procedure for the selection, application, and determination of the re-maining life in molded case circuit breaker is provided. Keywords: avail
3、able fault values, circuit breaker testing, molded case circuit breakers, molded case circuit breakers basics, molded case circuit breakers life, safety IEEE Recommended Practice for the Selection, Field Testing, and Life Expectancy of Molded Case Circuit Breakers for Industrial Applications Sponsor
4、 Petroleum and Chemical Industry Committee of the IEEE Industrial Applications Society The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyright 2005 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published
5、24 June 2005. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Copyright 2005 IEEE. All ri
6、ghts reserved.iiiIntroductionThis is a new standard that, for the first time, provides in one document the information that is necessary inorder to select, apply, and determine the remaining life of molded case circuit breakers. This standard isintended to be used by para-professionals and is not a
7、high-level engineering document.Notice to usersErrataErrata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL forerrata periodically.InterpretationsCurrent interpreta
8、tions can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/index.html.PatentsAttention is called to the possibility that implementation of this standard may require use of subject mattercovered by patent rights. By publication of this standard, no position is taken with
9、 respect to the existence orvalidity of any patent rights in connection therewith. The IEEE shall not be responsible for identifyingpatents or patent applications for which a license may be required to implement an IEEE standard or forconducting inquiries into the legal validity or scope of those pa
10、tents that are brought to its attention.ParticipantsThis following is a list of participants in the working group of the Petroleum and Chemical Industrial Com-mittee of the Industrial Applications Society:Gary L. Donner,ChairDonald ColaberardinoJohn GardnerGeorge D. GregoryDennis W. HeathClive W. Ki
11、mblinAndrew R. LeoniDaniel NeeserVincent SaporitaArthur J. Smith, IIIThis introduction in not part of IEEE Std 1458-2005, IEEE Recommended Practice for the Selection, Field Test-ing, and Life Expectancy of Molded Case Circuit Breakers for Industrial Applications.ivCopyright 2005 IEEE. All rights res
12、erved.The following members of the individual balloting committee voted on this standard. Balloters may havevoted for approval, disapproval, or abstention. The final conditions for approval of this standard were met on 24 January 2005. This standard was condi-tionally approved by the IEEE-SA Standar
13、ds Board on 8 December 2004, with the following membership:Don Wright,ChairSteve M. Mills, Vice ChairJudith Gorman,Secretary*Member EmeritusAlso included are the following nonvoting IEEE-SA Standards Board liaisons:Satish K. Aggarwal, NRC RepresentativeRichard DeBlasio, DOE RepresentativeAlan Cookso
14、n, NIST RepresentativeMichelle TurnerIEEE Standards Project EditorPaul AndersonWilliam AndersonHoward BradfieldDave BurnsDonald ColaberardinoGuru Dutt DhingraMike DarbyGary L. DonnerDonald DunnKimberly EastwoodC. James EricksonMichael J. FoleyCarl FredericksGeorge D. GregoryJohn Travis GriffithPaul
15、HamerRichard HulettBen JohnsonClive W. KimblinRoyce KingKevin LippertLisardo LouridoKeith MalmedalKenneth McclenahanDaleep MohlaPaul MyersDaniel NeeserKenneth NicholsonLorraine PaddenJohn PropstFrank RocchioJames RuggieriChet SandbergVincent SaporitaRobert TurnerS. Frank WatererBarry WoodDonald W. Z
16、ipseChuck AdamsStephen BergerMark D. BowmanJoseph A. BruderBob DavisRoberto de Marca BoissonJulian Forster*Arnold M. GreenspanMark S. HalpinRaymond HapemanRichard J. HollemanRichard H. HulettLowell G. JohnsonJoseph L. Koepfinger*Hermann KochThomas J. McGeanDaleep C. MohlaPaul NikolichT. W. OlsenRona
17、ld C. PetersenGary S. RobinsonFrank StoneMalcolm V. ThadenDoug ToppingJoe D. WatsonCopyright 2005 IEEE. All rights reserved.vContents1. Overview 11.1 Scope 11.2 Purpose. 12. Normative references. 13. Molded case circuit breaker basics 23.1 Molded case circuit breaker basics 23.2 Circuit breakers in
18、general. 23.3 Circuit breaker standards . 33.4 Contacts open and close. 43.5 Means to open and close contacts 43.6 Means to extinguish an arc 53.7 Means to respond to overcurrents/commands 73.8 Method for enclosing circuit breaker components. 83.9 Method for mounting circuit breaker. 93.10 Molded ca
19、se circuit breaker components. 113.11 Thermal conditions 123.12 Short-circuit conditions 133.13 Ground fault conditions . 143.14 Types of trip units 143.15 Circuit breaker selectivity 184. Molded case circuit breaker safety considerations 205. Selection of molded case circuit breakers 205.1 Standard
20、 rated molded case circuit breakers 215.2 100-Percent rated molded case circuit breakers. 225.3 Voltage rating election. 225.4 Current ratings . 235.5 Current rating selection 245.6 Selection of circuit breaker current rating . 245.7 Interrupting rating 266. Estimated available fault current at tran
21、sformer secondary. 267. Simplified method to calculate available fault current at transformer secondary . 287.1 METHOD 1: Simple approximation 297.2 METHOD 2: Accounting for cable between transformer and molded case circuit breaker 318. Procedures for field testing and determining the remaining life
22、 of molded case circuit breakers. 358.1 Rated current hold in test . 388.2 Exposed face and lug temperature check. 398.3 Mechanical operation tests. 398.4 Insulation resistance test 408.5 Individual pole resistance test (millivolt drop) 40viCopyright 2005 IEEE. All rights reserved.8.6 Inverse-time o
23、vercurrent trip test. 418.7 Instantaneous overcurrent trip test. 458.8 Accessory devices 46Annex A (informative) Bibliography. 47Copyright 2005 IEEE. All rights reserved.1IEEE Recommended Practice for the Selection, Field Testing, and Life Expectancy of Molded Case Circuit Breakers for Industrial Ap
24、plications1. Overview1.1 ScopeThis standard provides a recommended procedure for the selection, application, and determination of theremaining life in molded case circuit breakers. This recommended procedure is safe and easily understood.1.2 PurposeMolded case circuit breakers are one of the most wi
25、dely used circuit protection devices in low-voltage (lessthan 1000 volt) applications. In spite of their wide use in industry, the average person specifying, installing,operating and maintaining these devices has less than a complete understanding of them. The purpose of thisdocument is to provide p
26、eople who purchase or maintain molded case circuit breakers with a single docu-ment that includes the following information: How molded case circuit breakers operate How to correctly size and select molded case circuit breakers How to safely maintain molded case circuit breakers How to determine whe
27、n a molded case circuit breaker must be replaced 2. Normative referencesThis standard shall be used in conjunction with the following publications. The following referenced docu-ments are indispensable for the application of this standard. For dated references, only the edition citedapplies. For und
28、ated references, the latest edition of the referenced document (including any amendments orcorrigenda) applies. IEEE Std 242, The Buff BookIEEE Recommended Practice for Protection and Coordination of Indus-trial and Commercial Power Systems.1,2IEEEStd 1458-2005 IEEE RECOMMENDED PRACTICE FOR THE SELE
29、CTION, FIELD TESTING, AND LIFE2Copyright 2005 IEEE. All rights reserved.IEEE Std 1015, The Blue BookIEEE Recommended Practice for Applying Low-Voltage CircuitBreakers Used in Industrial and Commercial Power Systems.3. Molded case circuit breaker basicsThis clause describes the basic components of a
30、molded case circuit breaker and how the components work. 3.1 Molded case circuit breaker basics The topic of circuit breakers covers a very broad range of electrical devices, which have a number of thingsin common and an even larger number of dissimilar features and capabilities. The main groupings
31、selectedto cover circuit breakers are listed here as an introduction, without defining or explaining the individualgroupings at this point: Circuit breakers in general Industrial molded case circuit breakers (600 V and below) Miniature circuit breakers (240 V and below)Generally speaking, a circuit
32、breaker is a device that: Provides protection Opens and closes Might be removable Might be fixed Might be installed by itself in an enclosure Might be installed with other equipment Is applied at many voltage levelsCircuit breaker definitions vary depending upon the source of the definition.NEMA def
33、initionA circuit breaker is defined as a device designed to open and close a circuit by non-auto-matic means and to open the circuit automatically on a predetermined overcurrent, without injury to itselfwhen properly applied within its rating.ANSI definitionA circuit breaker is defined as a mechanic
34、al switching device, capable of making, carryingand breaking currents under normal circuit conditions and also making, carrying for a specified time andbreaking currents under specified abnormal circuit conditions such as those of short circuit.3.2 Circuit breakers in generalThe premise is the same
35、for both definitions and both are accurate, but the wording is quite different. Thesame is true with the many types of circuit breakers. Their general purpose is the same, but there are also anumber of significant differences. Circuit breakers come in what seems to be a never-ending array of sizes,
36、designs, ratings, and functions(Figure 1). In general, a circuit breaker provides switching capabilities and protection against one or moreovercurrent conditions. Examples of overcurrents are overloads, short circuits, and ground faults.1IEEE publications are available from the Institute of Electric
37、al and Electronics Engineers, Inc., 445 Hoes Lane, Piscataway, NJ 08854,USA (http:/standards.ieee.org/).2The IEEE standards or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers, Inc.IEEEEXPECTANCY OF MOLDED CASE CIRCUIT BREAKERS FOR INDUSTRIA
38、L APPLICATIONS Std 1458-2005Copyright 2005 IEEE. All rights reserved.3The circuit breaker might be applied as an individual item in its own enclosure or utilized in conjunctionwith a wide variety of other equipment in a common enclosure. Depending upon such things as system volt-age, type of circuit
39、 breaker, and specific application, circuit breakers in common enclosures with otherdevices might be called panelboards, switchboards, or switchgear, which are each specifically defined by aset of standards. They might even be referred to as just an assembly. An assembly could include some or allof
40、the following: circuit breakers, control devices, metering devices, regulating devices, equipment intercon-nections, and supporting structures.From a very broad perspective, all circuit breakers have the following common design and functionalcharacteristics: Compliance with specific standards Set of
41、 open/close contacts Means to open and close the contacts Means to extinguish an arc Means to respond to overcurrents/commands Method for enclosing circuit breaker components Method for mounting circuit breaker3.3 Circuit breaker standardsCircuit breakers are designed, built, and tested in accordanc
42、e with one or more specific sets of standards.The applicable standards might be domestic, international, or both. These standards actually categorize par-ticular types of circuit breakers. The governing standards are ANCE, ANSI, CSA, IEC, IEEE, NEMA, andUL. For a circuit breaker to be used, it shall
43、 comply with one or more specific sets of these standards.Figure 1A broad range of circuit breakersIEEEStd 1458-2005 IEEE RECOMMENDED PRACTICE FOR THE SELECTION, FIELD TESTING, AND LIFE4Copyright 2005 IEEE. All rights reserved.3.4 Contacts open and closeContacts in a circuit breaker provide a means
44、for isolating or connecting a part of a circuit from or with therest of the system. The contacts are like a wall switch that turns your lights on and off. In the case of a circuitbreaker, however, the number of contacts depends upon the circuit breaker application. For example, a threepole circuit b
45、reaker applied on a three-phase electrical system would have three sets of contacts. In general,circuit breaker contacts are provided in sets, one set per phase. A contact set is usually comprised of a fixedpart and a movable part. As a circuit breaker opens or closes, the fixed part of the contact
46、maintains its posi-tion, while the movable part moves to close (make) or open (break) the contact.3.5 Means to open and close contactsCircuit breakers utilize some type of operating mechanism to open and close the contacts just discussed.This operating mechanism can be mechanical or electro-mechanic
47、al.Depending upon the type of circuit breaker being considered, the operating mechanism could be called uponto Open and close the contacts manually Open and close the contacts on demand from a separate control or relay device Open the contacts automatically3.5.1 Opening and closing contactsLets cons
48、ider a three-phase circuit breaker of any kind. Designs are such that three sets of contacts open orclose simultaneously. This means that all the contacts are linked together in some manner. This part of themechanism might be connected mechanically in some fashion to a common handle. The handle, whe
49、n oper-ated, puts the mechanism into motion, and opens or closes the circuit breaker by opening or closing thecontacts. Circuit breakers, by virtue of their size and/or one or more standards requirements, need additional assis-tance to set the mechanism in motion and open or close the contacts as required. This additional assistancetakes the form of opening or closing springs. Springs play a big role in the precise functioning of circuitbreaker mechanisms. Springs are stretched or compressed to provide the energy necessary to assist wi
